This invention relates to a method of removing excess air from packages and to apparatus for carrying out the method.
When packages of loose material, such as rice, are sealed, the air remaining in the package will cause the package to balloon, for example due to air expansion in higher temperatures. Ballooning causes problems with downstream packaging equipment designed to place the packages into shipping containers and it also causes pallet stacks to become unstable. In order to prevent ballooning, it is known to puncture the packages at the time of sealing to allow the air to escape. However, this has the disadvantage that the holes allow direct insect ingress or allow insects to lay their eggs inside the packages causing infestation at a later date. This is clearly unacceptable. Most attempts to prevent ballooning by expelling air from the package prior to sealing have been unsuccessful.